System for generating radiofrequency currents



May 4 1926. 1,583,123

L. M. E. CLAUSING I SYSTB FOR GENERATING RADIO FREQUENCY CURRENTS Filed August 16, 1923 gwuawfoz Leroy M. E. Clavsin Patented May 4, 1926; V

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' 1 LEROY M, n. cLAUsINetoF cmcAeaiLLInoIs.

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Application filed August 16, 1923, Serial No. 657,746.

To all whom it may concern.-

ING, a citizen of the United States, residing at Chicago, 'inthe county of Cook, State" of Illinois, have madenewandfuseful Improvements in Systems for Generating Radiofrequency Currents, of which the following is a specification.

My invention relates generally to the generation of high frequency electrical currents, and more particularly tothe generation of V such currents for radio transmission in those types of generators employing thermionic vacuum tubes.

One common method of generating powerful high frequency currents is that of employing a relatively low power vacuum tube to generate the oscillations, and impresslng these oscillations upon one or more relatively high power vacuum tubes to amplify the oscillations. For instance a watt vacuum tube may generate the oscillations and impress them on a pair of 250 watt vacuum tubes for amplification before utilizing the oscillations in the transmitting circuits. Such a system is commonly termed a master oscillator-power amplifier transmitter.

In the figure, VT, and VT diagrammatically represent two three-electrode thermionic vacuum tubes employed as power amplifiers for the master oscillator vacuum tube VT, The plate circuits of the tubes VT, and VT are supplied with energy from an alternating current source S through the transformer T and secondary S,. The secondary S, is tapped at its middle point and the lead from this tap is common to the filaments of both tubes VT and VT,. The opposite terminals of secondary S, lead to the plates of these tubes. This arrangement provides for each tube alternately recti fying opposite half cycles of the alternating current plate supply. The secondary S of the transformer provides for a low voltage heating current for the filaments 'of the tubes VT and VT the resistances R, and R, providing a definite control over this heating current.

Both rectified halves of the source S are applied to the plate circuit of the vacuum tube VT through the auto transformer X, so that the vacuum tubes VT and VT in addition to performing the dual function of power amplification and self-rectification of the alternating current plate supply for their i own use, performathird function of rectify Be it known that I, LEROY M. E. CLAUsing an alternating current source for use on p the plate of themaster oscillator tube. The secondaryS, of the transformer T supplies low voltage-current to the filament of the. tube VT the value of the current being controlled by. the rheostat R The oscilla- .tions of the master oscillator are impressed upon the grids of the power amplifier tubes through connections containing the grid-leak and stopping-condenser combinations vGr, and G The condensers v O and C, provide by} passes for radiofrequency currents around the high frequency chokes S, and

The inductance L couples Withth-einductance L to'form a feed back for producing oscillations between the plate and grid circuitsof the tube VT The inductance L, couples with the inductance L to impress the oscillations-of the tube VT upon the grids of the amplifier tubes VT, andVT The condenser C, in connection with the inductance L permits of tuning the plate circuits of the oscillator tube.

Aillustrates an antenna coupled to the system throughthe inductances L, L,, and L permitting the antenna. to be excited with the oscillations from the power amplifier tubes. The antenna has the conventional earth connection E. The condenser C short circuited by a keying arrangement K, provides for making signals in telegraphic communication. This means can without invention be substituted by means well known to the art for telephonic modulation of the oscillations.

It will be seen that I have provided a system for producing high frequency electrical oscillations employing vacuum tubes without the use of special generators in the plate circuits of the tubes and also have avoided the use of separate rectifying devices by arranging for the power amplifier tubes to simultaneously perform three functions.

Having described my invention, I claim:

1. A system for generating high power high frequency electrical currents comprising a source of low frequency alternating currents, means for impressing said low frequency currents upon a vacuum tube with which are associated self oscillation producing circuits, means for impressing said low frequency currents upon a pair of vacuum tubes with which rectifying and amplifying circuits are associated, means associated with the said pair of vacuum tubes for impressing the said rectified currents upon the circuits of the first mentioned vacuum tube and'mea-n's for vimpressing the-oscillations in the circuits of sald tube on the circults of the said pair of vacuum tubes.

2. A system for generatlng high power high frequency electrical currents comprising a source oflow frequency alternating. currents, means-for impressing said currents cirupon the plate-filament and filament cuits of'a vacuum tube with whichare associated self' oscillation producing circuits, means for nnpressing said low frequency currents upon a pair of vacuum tubes, means .associatedwith said pair of vacuum tubes forthe simultaneous rectification of said low frequency: currents and amplification of oscillations produced in the first mentioned vacuum tube.

3. Asyst'em for generating and radiating high power radio signals-comprising a source for im ressin the said rectified currents.

upon the first mentioned vacuum tube, means associated with first mentionedvacuum tube for impressing the oscillations in a circuit of said vacuum tube on the amplifying circuits of the-said pair of vacuum tubes, means associated with the last'mentioned means for creating variations in the oscillations of the first mentioned tube to correspond to sig nals, and means associated with the said pair of vacuum tubes for, impressing the varied amplified oscillations in the circuits of said tubes upon a radiatingsystem.

LEROY M. E. CLAUSING. 

